Leisure venues Brewhouse & Kitchen and Popworld have joined soon after their openings in the rebranded 12thStreet.
Also on the DMK membership list now is Stantonbury Theatreand Ride High Equestrian Centre, the taxi firm Orcars and Aqua Parcs, the water-based play venue at Willen Lake.
Global events company Events Together, based in Milton Keynes, has also joined with a view to promoting its LGBTQ+ conference taking place in Milton Keynes in October.
DMK chief executive Steven Gordon-Wilson said: “It is great to see such a varied range of companies discovering the benefits membership can bring them. We are a not-for-profit organisation so rely on our membership to allow us to continue promoting Milton Keynes as a leisure and business destination.”